Washing machine lid switch assembly

ABSTRACT

A lid switch for disabling a top loading washing machine when the lid is raised is provided in which an arcuate arm passing downward from the lid near the hinge of the lid curves around the hinge axis into a space behind the lid under the top surface of the washing machine. A switch positioned above this top surface and having a downwardly extending operator may be actuated by this arm, the arm which serves to trap water from the washing machine tub area and by passing through a rim extending downward into the tub resists tampering with the switch. In one embodiment, the arcuate arm strikes a rocker arm permitting further displacement of the switch away from the tub. The rocker arm may be in two halves which pivot with respect to each other held in angular relationship by a detent. The switch assembly may be made self-adjusting by bending this adjustable rocker arm to small angle allowing the detent to release under the force of the arcuate arm after the switch has reached its stop position adjusting the rocker arm to the correct angular configuration.

FIELD OF THE INVENTION

The present invention relates to electrical switch assemblies used withresidential clothes washing machines and the like to stop the operationof the machine when the lid is raised. Specifically, the inventionrelates to a switch assembly which resists tampering and reduces thepossibility of contamination of the electrical contacts of the switch bywater, soap or lint.

BACKGROUND OF THE INVENTION

Top loading residential washing machines provide an upwardly open tubinto which clothes and detergent may be placed for cleaning. Duringoperation, the tub and its internal spin basket are filled with water,via a solenoid valve, and a central agitator within the tub agitates theclothes and the water to separate the dirt from the fabric (the"agitation cycle"). At the conclusion of the agitation cycle, the wateris drained from the tub and the spin basket is spun about its axis toremove the water from the wet clothes by centrifugal force (the "spincycle").

During the spin cycle, it is important that the tub be covered toprevent injury to the user. For this reason, a hinged lid is provided tocover the opening of the tub during operation of the washing machine.The lid may be connected to an electrical switch (a "lid switch") sothat if the lid is opened during the agitation or spin cycles, thewashing machine stops.

It is known to position the lid switch on the underside of the top ofthe washing machine in an area underneath the lid when the lid isclosed. A pin extending downward from the lid activates the lid switch,when the lid is closed, to permit operation of the washing machine.

The maximum sensitivity of the lid switch is obtained by positioning thelid switch beneath the front edge of the lid furthest from the lid'shinge. In this position, a pin attached to the lid for activating thelid switch, will have the greatest possible motion when the lid islifted.

Unfortunately, in this position, the lid switch is particularlyvulnerable to water and detergent splash. Further, because the switch isreadily apparent, the risk of it being defeated with a pencil or otherpointed instrument (so as to operate the washing machine while the lidis open) is increased.

These problems can be avoided somewhat by moving the switch to aposition closer to the hinge. However, in this position, the reducedmotion of the lid makes it difficult to provide switching during theearly stages of opening the lid because of the lack of travel close tothe hinge point.

SUMMARY OF THE INVENTION

The present invention provides a lid switch assembly that resiststampering and that minimizes exposure of the switch to contamination.This is accomplished, in a first embodiment, by means of an arcuate armpositioned near the hinge of the lid to curve downward away from the lidand upward about the hinge axis. Motion of the arm with the lid armactuates a downward extending operator of a switch behind the wall.

More specifically, the present invention provides a switch assemblyincluding an arcuate arm attached to a first end of the lid andextending downward therefrom about the hinge axis to a second end, and aswitch having a contact assembly linked with a downward extendingoperator. The operator is positioned with respect to the hinge so as tobe pushed upward by the second end of the arcuate arm when the lid is inthe closed position and so that the operator returns downward when thelid is in the open position.

It is one object of the invention to provide an improved lid switchassembly for top loading washing machines and the like having improvedresistance to contamination from water, soap and lint. The arcuate shapeof the arm provides a trap against passage of water from the lid area tothe switch. This is furthered by mounting the switch in invertedconfiguration so that the switch contacts are above the operatoractuated by the arm. The arm also provides a lever to increase themovement of the switch operator as the lid is opened, increasing thesensitivity of the switch to the opening lid and allowing the switch tobe removed from the immediate area of the tub.

The arcuate arm may pass through a slot in the top rim for a lengthwhich has a constant radius about the hinge axis. The opening of theslot may conform substantially to the cross section of the arcuate arm.

Thus, it is another object of the invention to provide a lid switchassembly that resists tampering. The slot may be relatively narrow andmay be fully occupied by the arcuate arm preventing the user frominserting a tool through the slot to defeat the switch. Further, becausethe path of the arcuate arm curves, a straight tool inserted in the slotwill not properly locate the operator of the switch.

A rocker arm may be interposed between the arcuate arm and the operatorof the switch to permit the switch to be moved further away from the tubarea. The rocker arm may have a first and second end separated by afulcrum point and be positioned with respect to the lid hinge so thatthe first end of the rocker arm is pushed upward by the second end ofthe arcuate arm when the lid is in the closed position and so that thefirst end of the rocker arm may return downward when the lid is in theopen position. The operator may be pivotally linked to the second end ofthe rocker arm so as to be pulled downward by the second end to a stoppoint when the lid is in the closed position and so as to retract upwardwhen the lid is in the open position.

It is therefore another object of the invention to permit the switch tobe further removed from the tub area.

The rocker arm may include a barbed projection extending upward from thefulcrum point to be received within a hole in the top of the washingmachine to loosely suspend the rocker arm from the top so that it maypivot about the fulcrum point. The rocker arm may be a single pieceplastic part. The second end of the rocker arm may be forked to receivea notched operator.

Thus it is another object of the invention to provide a means forinterconnecting the arcuate arm and the switch that is both inexpensiveand that allows the arm to be easily installed. The barbed projection,once inserted within the hole in the top, locks itself in place andprovides the necessary freedom of motion to rock under the influence ofthe arcuate arm. The forked end of the rocker arm and notched operatorallow the two to be quickly connected thus holding the rocker arm inalignment without the need for a separate hinge assembly.

The rocker arm may include a first and second rocker arm half providingthe first and second ends respectively and joined pivotally with respectto each other at the fulcrum point. A detent between the first andsecond rocker arm halves may permit pivoting of the first and secondrocker arms with respect to each other but only for forces greater thanthat required to pull the operator downward to the stop point.

Therefore, it is another object of the invention to provide for aself-adjusting lid switch. Prior to assembly, the first and secondrocker arm halves are adjusted to a greater angle than is requiredduring operation. The first time the lid is closed, the arcuate armengages the first end of the rocker arm moving the operator of theswitch downward until it reaches the stop. At that point, the detentreleases allowing the rocker arm first and second halves to pivot withrespect to each other to provide an automatic adjustment of their angleto the particular assembly.

The foregoing and other objects and advantages of the invention willappear from the following description. In the description, reference ismade to the accompanying drawings which form a part hereof and in whichthere is shown by way of illustration, a preferred embodiment of theinvention. Such embodiment does not necessarily represent the full scopeof the invention however, and reference must be made therefore to theclaims herein for interpreting the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a top loading residential washingmachine having a rear console and showing a lid in an open position toreveal the arcuate arm of the present invention;

FIG. 2 is a cross section along lines 2--2 of FIG. 1 showing the arcuatearm positioned to pass through a slot in the top rim to push a rockerarm attached to a switch within the console;

FIG. 3 is a figure similar to that of FIG. 2 but showing the lid in theclosed position;

FIG. 4 is a perspective view of the rocker arm of FIG. 3 as may bemolded in a single piece plastic part;

FIG. 5 is an alternative embodiment of the present invention without therocker arm and with the switch moved to a position closely adjacent tothe lid;

FIG. 6 is a side elevation view of a second embodiment of the rocker armof FIG. 3 providing self-adjustment of the switch assembly;

FIG. 7 is a bottom view of the rocker arm of FIG. 6 showing the detentbetween halves of the rocker arm;

FIG. 8 is a fragmentary, perspective view of the top loading washingmachine of FIG. 1 showing the lid mounted to open to the side of thewashing machine and with a rocker arm axis perpendicular to the hingeaxis; and

FIG. 9 is a top view of the rocker arm of FIGS. 4, 6 and 7 from abovethe top of the washing machine showing a keyhole through which a barbedprojection of the rocker arm may be inserted.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1, a top loading washing machine 10 providesgenerally a tub 12 into which clothes may be loaded and washed under theinfluence of center agitator 14. Access to the tub 12 is providedthrough a circular opening in a generally planar and horizontal top 16.The circular opening conforms substantially to the opening of the tub 12and is ringed by a top flange 18 extending downward from the circularopening a short distance into the tub 12 to guide clothes into the tub12.

A square lid 20 may be closed to a horizontal position abutting the top16 within a shallow recess 19 formed in the top 16. The recess 19 isequal in area to the lid 20 so that the lid 20 may be closed to liewithin the recess 19 flush with the top 16. Water dripping from wetclothes removed from the tub 12 to the top 16 will be largely collectedby the recess 19. The lid 20 includes a downwardly extending lip 21providing the lid 20 with additional stiffness and a finished edge.

The lid 20 may open to a substantially vertical orientation by means ofa hinge (not shown) rotating one edge of the lid 20 about a hinge axis22 along a rear edge of the lid 20. A console 24 supporting the controlsof the washing machine 10 is positioned at the rear edge of the top 16of the washing machine 10 behind the lid 20 when it is open.

Referring now to FIGS. 1 and 2, a switch assembly 11 includes an arcuatearm 26 attached to the underside of the lid 20 near the hinge axis 22and centered along the rear edge of the lid 20. The arcuate arm 26extends downward from the lid 20 when the lid 20 is in the closedposition and generally curves rearward about the hinge axis 22 to passthrough a slot 30 in the top flange 18 as the lid 20 is opened andclosed. The arcuate arm 26 may be constructed from an injection moldedplastic to provide a generally rectangular cross section conforming tothe outline of the slot 30 and secured to the lid 20 by a screw 32passing through the lip 21 of the lid 20 and into the arcuate arm 26.The screw 32 may be inserted through the lip 21 prior to assembly of thelid 20 to the washing machine 10 to be inaccessible to the user innormal use.

Referring now to FIG. 3 and 4, when the lid 20 is in the closedposition, a free end 34 of the arcuate arm 26 passes through the slot 30and moves upward to approach a point proximate to the underside of thetop 16 of the washing machine 10 and to push against a first end of arocker arm 36 upward causing a second end of the rocker arm 36 to movedownward about a rocker arm axis 37. The second end of the rocker arm 36is attached to the switch operator 38 of a switch 40 pulling theoperator down to close a set of electrical contacts (not shown) withinthe switch 40. These contacts are typically wired in series with thewashing machine motor to prevent agitation or spin drying of the clotheswhen the lid is open.

In operation, the rocker arm 36 presses against the underside of the top16 at a ridge fulcrum 48 at the middle top of the rocker arm 36. Therocker arm is held to the top 16 by means of a barbed projection 50passing upward from the fulcrum 48 through a hole 52 in the top 16. Thebarbed projection 50 is forced through the hole 52 by compressing itsbarb inward against the body of the barbed projection 50. After thebarbed projection 50 is so inserted, the barb may spring outward, as aresult of the natural elasticity of the material of the barbedprojection 50, locking the rocker arm 36 in position.

Alternatively, as shown in FIG. 9, the hole 52 may be cut in a "keyhole"shape having side slots 51 opposed across the center of the hole 52 topermit passage of the barbs of the barbed projection 50 into the hole 52without deflection of the barbs, when the rocker arm 36 and hence thebarbed projection, is rotated to a first position about its axis ofinsertion into hole 52. Rotation of the rocker arm 36 by 90° then locksthe rocker arm 36 to the top 16.

In the preferred embodiment, the hole 52 in the top 16, used to attachthe rocker arm 36 to the top 16, is positioned beneath the console 24 soas to be removed from access by the user and somewhat protected fromsplashing and contamination. The hole 52 is somewhat larger than thebarbed projection 50 so as not to interfere with a rocking back andforth of the rocker arm 36.

The second end of the rocker arm 36 co-acts with the switch operator 38by means of a fork 44 which fits around the cylindrical switch operator38 within a notch formed between two cylindrical collars 46. Thus,assembly of the rocker arm 36 to the washing machine 10 requires no morethan a fitting of the fork 44 onto the switch operator 38 and pressingthe barbed projection 50 through the hole 52. Together the barbedprojection 50 and the interfitting of the fork 44 and switch operator 38hold the rocker arm 36 against rotation about the barbed projection 50to ensure alignment of the rocker arm 36 and the free end 34 of thearcuate arm 26, but yet permit rocking action under the influence of thearcuate arm 26.

The entire rocker arm, including the barbed projection 50, may beadvantageously molded in a single piece from plastic.

Referring again to FIGS. 2 and 4, the switch operator 38 of the switch40 passes out of the body of the switch through a flexible bellows 42,the latter of which serves to further seal contaminants, includingwater, out of the switch 40. The switch 40 incorporates an internalspring to retract the switch operator 38 and open the internal contactsabsent force downward on the operator by the rocker arm 36. Thus, whenthe lid 20 is in the open position as shown in FIG. 2, with the end 34of the arcuate arm removed from the rocker arm 36, the switch operator38 retracts upward opening the contacts and stopping operation of thewashing machine motor.

The mounting of the switch 40 is such that the contacts within the bodyof the switch are generally above the top 16 of the washing machine 10with the operator extending downward out from the body of the switch 40and through a hole in the top 16 to a position beneath the top 16. Thusthe mounting of the switch 40 is such that gravity-induced drainage isin a direction opposing contamination of the switch 40 by water and thelike from the tub of the washing machine 10. Further, it will be notedthat, in the closed position of the lid 20, the arcuate arm 26 providesa U-shaped trap for water splashed from the tub area, which as a resultof the U-shape cannot flow upward to the rocker arm 36. The small sizeof the slot 30 in the top flange 18 also provides a barrier to thecontamination of the switch 40.

It will be appreciated also that the slot 30, as is normally obstructedby the arcuate arm 26, renders it difficult for the user to tamper withthe switch 40 by passing instruments through the slot 30.

Referring now to FIGS. 6 and 7, the switch assembly 11 of FIGS. 2 and 3may be made self-adjusting by the use of a rocker arm 36' composed of afirst and second rocker arm half, 54 and 56 respectively, pivoted near aridge fulcrum 48 about a rivet 58 to move between a first and secondconfiguration. The first rocker arm half 54 includes the fork 44, whichmay interfit with the switch operator 38 of the switch 40, and thebarbed projection 50 attaching the rocker arm 36 to the top 16. Thisrocker arm half 54 may be advantageously molded in a single piece fromthermoplastic material.

The second rocker arm half 56 may be fabricated from sheet stainlesssteel folded into a shallow channel cross-section having wings 59 toembrace the right and left sides 61 of the first rocker arm half 54 andto be pivotally held in place by the rivet 58. As is best seen in FIG.7, the inner surface of the wings 59 of the second rocker arm half 56includes a set of inwardly projecting teeth 60 which engagecorresponding outwardly extending teeth 62 formed in the left and rightsides 61 of the first rocker arm half 54 where it is overlapped by thesecond rocker arm half 56.

Pivoting motion of the first rocker arm half 54 with respect to thesecond rocker arm half 56 about the rivet 58 is resisted by the teeth 60and 62 forming detent surfaces until the force between the rocker armhalves 54 and 56, in the form of a torque about the rivet 58 issufficient to resiliently deflect the wings 59 of the rocker arm half 56outward permitting teeth 60 to pass by teeth 62. The torque necessary topermit pivoting motion of the first rocker arm half 54 with respect tothe second rocker arm half 56 about the rivet 58 is set to be greaterthan that necessary to actuate switch 40. Alternatively, the teeth maybe replaced with a pair of contacting frictional surfaces providing thesame controlled pivoting.

The first and second halves 54 and 56 of the rocker arm 36' areinitially positioned so that the angular relationship measured betweenthe first and second rocker arm halves 54 and 56, from the bottom sideof the rocker arm 36', is less than that which would be expected duringnormal operation of the switch assembly 11. When the free end 34 ofarcuate arm 26 presses on the end of the second half of the rocker arm36', forcing that end upward as indicated by arrow 64, the opposite endof the rocker arm 36', of rocker arm half 54, attached to switchoperator 38, moves switch operator 38 downward until a mechanical stopposition of the switch 40 is reached. At this point, the torque aboutrivet 58 between the first and second rocker arm halves 54 and 56increases to a predetermined point that permits slippage of the detentsurfaces of teeth 60 and 62 past each other to accommodate additionaltravel of the free end 34 of the arcuate arm 26. The pivoting of thefirst rocker arm half 54 with respect to the second rocker arm half 56about the rivet 58 sets the precise angle between the first and secondhalves of the rocker arm 36 required for full extension of the switchoperator 38 with closure of the lid 20. This precise adjustment aids inproviding rapid turnoff of the motors of the washing machine 10 withsmall angular opening of the lid 20.

The amount the lid 20 must be opened to turn off the motor of thewashing machine 10 will be equal to the distance the switch operator 38moves upward between full extension (at the stop position) and a switchpoint position a small amount above the stop position, multiplied by thelever ratio provided by the arcuate arm 26 and the rocker arm 36.

The torque required for pivoting motion of the first rocker arm half 54with respect to the second rocker arm half 56 about the rivet 58 may beset by selection of the material and gauge of the second rocker arm (andhence the flexibility of the wings 59), the size and number of the teeth60 and 62, and the closeness of the fit between the first rocker armhalf 54 and the second rocker arm half 56. Slots 63 permit fine tuningof the effective flexibility of the wings 59.

Referring now to FIG. 5, in some models of washing machine 10', theconsole may more closely abut the recess 19 holding the lid 20, so thatthe rocker arm 36 may be dispensed with and the arcuate arm 26 may actupon the switch operator 38' of the switch 40'. Here the switch 40'closes its contacts with upward motion of the switch operator 38 incontrast to the switch 40 described with respect to FIGS. 2 and 3. Againthe features of tamper resistance and reduction of contamination ofwater, soap, and lint from the tub is provided by the arcuate arm 26.

Referring now to FIG. 8, the lid 20 may open to one side of the washingmachine 10 so that the hinge axis 22 lies generally along a right sideof the top 16. In this case, the arcuate arm 26", as attached to theunderside of the lid 20, is displaced to the rear edge of the lid 20 andextends downward through a slot 30" in a horizontal surface of thebottom of the recess 19. For this reason, the arcuate arm 26" maintainsa constant radius about the hinge axis 22 starting at the point where itfirst extends downward from the bottom surface of the lid 20.

When the lid 20 is in the closed position, the free end 34 of thearcuate arm 26" approaches a point beneath the top 16 to the right sideof the washing machine 10 to push upward against the first end of therocker arm 36 which is now displaced to the right side of the washingmachine 10. As before, the other end of the rocker arm 36 attaches to aswitch 40 positioned under the console 24. In this case, the rocker armaxis 37 is perpendicular to the hinge axis 22.

The above description has been that of a preferred embodiment of thepresent invention. It will occur to those that practice the art thatmany modifications may be made without departing from the spirit andscope of the invention. In order to apprise the public of the variousembodiments that may fall within the scope of the invention, thefollowing claims are made.

I claim:
 1. A switch assembly for a top-loading washing machine having alid hinged at one edge to move about a hinge axis between a closedposition with the lid substantially aligned with the top surface of thewashing machine and an open position where an edge of the lid oppositethe hinged edge is raised with respect to its position when the lid isclosed the switch assembly comprising:a) an arcuate arm attached at afirst end to the lid and extending downward therefrom below the topsurface of the washing machine when the lid is closed and extendingabout the hinge axis to a second end; b) a switch having a contactassembly linked with a downward extending operator, the operator beingpositioned with respect to the hinge so as to be pushed upward by thesecond end when the lid is in the closed position and so that theoperator returns downward when the lid is in the open position; wherebythe force of gravity prevents water on the lid and arcuate arm fromflowing to the contact assembly of the switch.
 2. A switch assembly fora top-loading washing machine having a lid hinged at one edge to moveabout a hinge axis between a closed position with the lid substantiallyaligned with the top surface of the washing machine and an open positionwhere an edge of the lid opposite the hinged edge is raised with respectto its position when the lid is closed, the switch assemblycomprising;a) an arcuate arm attached at a first end to the lid andextending downward therefrom about the hinge axis to a second end; b) aswitch having a contact assembly linked with a downward extendingoperator, the operator being positioned with respect to the hinge so asto be pushed upward by the second end when the lid is in the closedposition and so that the operator returns downward when the lid is inthe open position; whereby the force of gravity prevents water on thelid and arcuate arm from flowing to the contact assembly of the switch;and including a rim surrounding a tub opening, the rim having a slot forslidably admitting a length of the arcuate arm and wherein the length ofthe arcuate extends about the hinge axis at a constant radius so thatthe slot may substantially conform to the cross section of the arcuatearm preventing the introduction of foreign matter through the slot. 3.The switch assembly of claim 2 where in the length of the arcuate arm isselected so that the slot is occupied by the arcuate arm at allpositions of the lid between the open position and the closed position.4. The switch assembly of claim 1 wherein the switch is mounted to thetop of the washing machine with the contacts positioned above the topand the operator extending below the top.
 5. The switch assembly ofclaim 1 wherein the top surface of the washing machine has a portioncovered by a console and wherein the switch is mounted to be covered bythe console.
 6. A switch assembly for a top-loading washing machinehaving a lid hinged at one edge to move about a hinge axis between aclosed position with the lid substantially aligned with the top surfaceof the washing machine and an open position where an edge of the lidopposite the hinged edge is raised with respect to its position when thelid is closed, the switch assembly comprising:a) an arcuate arm attachedat a first end to the lid and extending therefrom about the hinge axisto a second end; b) a rocker arm having a first and second end separatedby a fulcrum point, the fulcrum point locating a rocker arm axis aboutwhich the rocker arm may pivot, the rocker arm positioned with respectto the hinge so that the first end of the rocker arm is pushed upward bythe second end of the arcuate arm when the lid is in the closed positionand so that the first end of the rocker arm may return downward when thelid is in the open position; a switch having a contact assembly linkedwith a downward extending operator, the operator being pivotally linkedto the second end of the rocker arm so as to be pulled downward by thesecond end to a stop point when the lid is in the closed position and soas to retract upward when the lid is in the open position; whereby theforce of gravity prevents water on the lid and arcuate arm from flowingto the contact assembly of the switch.
 7. The switch assembly of claim 6wherein the hinge axis is substantially perpendicular to the rocker armaxis.
 8. The switch assembly of claim 6 wherein the hinge axis issubstantially parallel to the rocker arm axis.
 9. The switch assembly ofclaim 6 wherein rocker arm includes an upward extending barbedprojection extending from the fulcrum point to be received within a holein the top to loosely suspend the rocker arm from the top so that it maypivot about the rocker axis.
 10. The switch assembly of claim 9 whereinthe hole is asymmetrical and the barbed projection shaped to be receivedwithin the hole without interference when the barbed projection isrotated about an insertion axis to a first position, but so that thebarbed projection cannot be removed from the hole when the barbedprojection is rotated about the insertion axis to a second positiondifferent from the first position.
 11. The switch assembly of claim 6wherein the rocker arm is a single-piece plastic part.
 12. The switchassembly of claim 6 wherein the rocker arm includes:i) a first andsecond rocker arm half, providing the first and second endsrespectively, the halves joined to pivot with respect to each other atthe fulcrum point by a flexible joint; and ii) a detent between thefirst and second rocker arm halves permitting pivoting of the first andsecond rocker arm halves with respect to each other only for forcesgreater than that required to pull the operator downward to the stoppoint.
 13. The switch assembly of claim 6 including a top rim having aslot for slidably admitting a length of the arcuate arm and wherein thelength of the arcuate extends about the hinge axis at a constant radiusso that the slot may substantially conform to the cross section of thearcuate arm preventing the introduction of probes and foreign matterthrough the slot.
 14. The switch assembly of claim 6 wherein the switchis mounted to the top of the washing machine with the contactspositioned above the top and the operator below the top.
 15. The switchassembly of claim 6 wherein the top surface of the washing machine has aportion covered by a console and wherein the switch is mounted to becovered by the console.